This invention relates to a process for paraffin-olefin alkylation producing highly branched paraffins under strong acid catalyzed conditions and in the presence of adamantane hydrocarbons as hydride transfer catalysts.
Alkylation of olefins by carbonium ions under strong acid conditions is a well-known process for producing a wide variety of useful hydrocarbon materials and particularly, gasoline additives. For example, trimethylpentanes are common additives used for blending into gasoline for octane improvement which can be produced by alkylating isobutylene with isobutane in sulfuric acid or liquid HF. An example of an acid catalyzed reaction process is described in U.S. Pat. No. 3,231,633.
Hydrocarbon conversion processes employing novel Lewis acid systems are disclosed in U.S. Pat. No. 4,229,611 and 4,162,233, both assigned to Exxon Research and Engineering Company.
U.S. Pat. No. 3,671,598 describes a process for isomerizing saturated cyclic hydrocarbons under strong acid conditions in the presence of an adamantane hydrocarbon. However, no suggestion is made that an adamantane compound might be useful in paraffin-olefin alkylation under strong acid conditions.
New methods for producing alkylated paraffinic hydrocarbons useful as octane improvement agents are constantly being searched for in an effort to increase product quality, yield and reaction rate, while lowering acid consumption and decreasing the cost of said process.